The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, a functional block diagram of an engine system 100 is presented. Air is drawn into an engine 102 through an intake manifold 104. The volume of air drawn into the engine 102 is varied by a throttle valve 106, which is actuated by an electronic throttle control (ETC) motor 108. The air mixes with fuel from one or more fuel injectors, such as the fuel injector 110, to form an air/fuel (A/F) mixture. The A/F mixture is combusted within one or more cylinders 112 of the engine 102 to generate torque. For example only, combustion may be initiated by spark from a spark plug 114. Resulting gas is expelled from the engine 102 to an exhaust system 115.
The fuel is stored in a fuel tank 116 prior to being brought to the engine 102 to be combusted. A modular reservoir assembly (MRA) 118 is disposed within the fuel tank 116 and includes a fuel pump 120. The fuel pump 120 provides fuel to the fuel injectors via a fuel rail 122. The fuel is filled into the fuel tank 116 through an inlet 124. A fuel cap 126 seals the inlet 124 and the fuel tank 116.
Fuel vapor may accumulate in the fuel tank 116 for various reasons, such as heat, radiation, and/or vibration. Fuel vapor travels from the fuel tank 116 through a vapor line 128 to a vapor canister 130, which stores the fuel vapor. The canister 130 may include, for example, an active charcoal that absorbs the fuel vapor. The canister 130 may also include a vent valve 132, which may be actuated to allow air into the canister 130.
The operation of the engine 102 creates a vacuum within the intake manifold 104. A second vapor line 134 connects the canister 130 to the intake manifold 104 via a purge valve 136. The purge valve 136 is actuated to draw (purge) the stored fuel vapor, from the canister 130, into the intake manifold 104. This fuel vapor forms part of the A/F mixture and may be combusted within the cylinders.